There exists need for refractory moldable compositions capable of withstanding high temperatures which can be readily formed into a variety of shapes. Such refractory moldables may be used in many applications including, by way of example only, filling and repair of expansion joints in refractory construction, hot patching of refractory lining in kiln and boiler tube walls, and in building construction as a fire retardant seal.
Known refractory moldable compositions such as those described in U.S. Pat. Nos. 4,248,752 and 4,174,331 to Myles are capable of withstanding high temperature and can be formed into a variety of shapes. However, these known moldables have a relatively high viscosity which limits their application, particularly through hydraulic means such as pumping or caulking. Additionally the cost of these known moldables is relatively high. In many applications, the cost of the moldable compositions taught by Myles may not be economically justified. The present invention provides refractory moldable compositions useful as thermal insulation at temperatures up to 1650.degree. C. Another problem with known refractory moldable compositions is their lack of resilience upon drying and setting. In many applications, the amount of resilience inherent in known refractory moldables is inadequate to withstand the thermal expansion and contraction inherent in the operational cycle of the apparatus to which the refractory composition is applied and separate therefrom during service. Certain embodiments of refractory moldable compositions, according to the present invention, provide greater resiliency and resistance to cracking or separation from the surface to which they have been applied.